Lady in Blue is a fairly tall, light pink fish. She has orange hair, and wears a green dress and white gloves and boots. She also wears a light brown hat with a green stripe on it, and pink lipstick. She also wears purple eyeliner.
In "The Great Patty Caper," she was one of the four suspects (only one of the four suspects that wasn't disguised and wasn't a criminal or investigated) for stealing the key to the vault in which the recipe is hidden. She also appears in the episode "The Krabby Patty That Ate Bikini Bottom" with her pet worm that is named Snookiems. However, the Krabby Patty ate her, her hat being the only thing left. She was later spat out of the Krabby Patty along with Snookiems.